Objective: To describe 8 y weight change in Chinese adults and to determine the baseline characteristics of those who gained weight.
Design: A population-based cohort study of weight change and its predictors from 1989 to 1997.
Participants: A cohort of 2488 adults aged 20-45 in 1989 drawn from seven provinces in China using multistage, random cluster sampling.
Measurements: Weight change over 8 y was the outcome variable. The key exposures were baseline energy intake, physical activity at work, alcohol consumption and smoking status. Baseline weight, weight status, height, age, residence, income and educational attainment were control variables.
Results: Overweight (body mass index, BMI>or=25 kg/m(2)) doubled in females (10.4-20.8%) and almost tripled in males (5.0-14.1%). Low physical activity was a strong predictor of weight gain. Compared to those whose weight remained stable (+/-2 kg/8 y), males and females who experienced large weight gain (>5 kg/8 y) were 3 and 1.8 times more likely to engage in light rather than heavy work-related physical activity.
Conclusion: The prevalence of overweight increased dramatically in this cohort. Light work-related physical activity was the strongest predictor of this weight gain.